Cytomegalovirus Anterior Uveitis: Clinical Manifestations, Diagnosis, Treatment, and Immunological Mechanisms

Ocular Toxoplasmosis: Advances in Toxoplasma gondii Biology, Clinical Manifestations, Diagnostics, and Therapy

Toxoplasma gondii, an obligate intracellular parasite, is a globally prevalent pathogen capable of infecting a wide range of warm-blooded animals, including humans. Ocular toxoplasmosis (OT), a severe manifestation of T. gondii infection, can lead to potentially blinding complications. This comprehensive review delves into the current understanding of T. gondii biology, exploring its complex life cycle, diverse transmission routes, and strain diversity. This article provides an in-depth analysis of the clinical manifestations of OT, which can result from both congenital and acquired infections, presenting a spectrum of signs and symptoms. The review examines various diagnostic strategies employed for OT, including clinical examination, multimodal imaging techniques such as fundus fluorescein angiography (FFA), indocyanine green angiography (ICGA), optical coherence tomography (OCT), and optical coherence tomography angiography (OCTA), as well as laboratory tests including serology and molecular methods. Despite extensive research, the specific mechanisms underlying ocular involvement in T. gondii infection remain elusive, and current diagnostic options have limitations. Moreover, the treatment of active and recurrent OT remains a challenge. While existing therapies, such as antimicrobial agents and immunosuppressants, can control active infections, they do not offer a definitive cure or completely prevent recurrence. The clinical endpoints for the management of active and recurrent OT are also not yet well-established, and the available treatment methods carry the potential for adverse effects. This article highlights the need for future research to elucidate the pathogenesis of OT, investigate genetic factors influencing susceptibility to infection, and develop more sensitive and specific diagnostic tools. Enhancing global surveillance, implementing robust prevention strategies, and fostering multidisciplinary collaborations will be crucial in reducing the burden of OT and improving patient outcomes. This comprehensive review aims to provide a valuable resource for clinicians, researchers, and policymakers, contributing to a better understanding of T. gondii infection and its impact on ocular health.

Cytomegalovirus Retinitis: Clinical Manifestations, Diagnosis and Treatment

Cytomegalovirus (CMV) retinitis is the most common eye disease associated with CMV infection in immunocompromised individuals. The CMVR may initially be asymptomatic; however, relatively mild vitreous inflammation at the onset may be an important differential point from other diseases in HIV patients. Fundus photography, CD4 T-cell count, and telemedicine could be used to screen and monitor the high-risk population, particularly in resource-limited regions. Retinitis generally starts in the peripheral retina and advances toward the posterior pole, which could develop to the characteristic "pizza pie" appearance marked by central retinal necrosis and intraretinal hemorrhage. CMVR causes vision loss if left untreated, and early antiviral therapy significantly reduces the risk of vision loss. Alongside traditional antiviral treatments, immunotherapies including CMV-specific adoptive T-cell therapy and CMV immunoglobulin (CMVIG) are emerging as promising treatment options due to their favorable tolerability and reduced mortality. This review comprehensively examines CMV retinitis, encompassing the clinical features, differential diagnosis, laboratory tests, and updated treatment strategies to inform clinical management.

Immune surveillance of cytomegalovirus in tissues

Cytomegalovirus (CMV), a representative member of the Betaherpesvirinae subfamily of herpesviruses, is common in the human population, but immunocompetent individuals are generally asymptomatic when infected with this virus. However, in immunocompromised individuals and immunologically immature fetuses and newborns, CMV can cause a wide range of often long-lasting morbidities and even death. CMV is not only widespread throughout the population but it is also widespread in its hosts, infecting and establishing latency in nearly all tissues and organs. Thus, understanding the pathogenesis of and immune responses to this virus is a prerequisite for developing effective prevention and treatment strategies. Multiple arms of the immune system are engaged to contain the infection, and general concepts of immune control of CMV are now reasonably well understood. Nonetheless, in recent years, tissue-specific immune responses have emerged as an essential factor for resolving CMV infection. As tissues differ in biology and function, so do immune responses to CMV and pathological processes during infection. This review discusses state-of-the-art knowledge of the immune response to CMV infection in tissues, with particular emphasis on several well-studied and most commonly affected organs.

Applications of Biological Therapy for Latent Infections: Benefits and Risks

Biological therapies have revolutionized medical treatment by targeting the key mediators or receptors involved in inflammatory responses, thereby effectively suppressing inflammation and achieving beneficial outcomes. They are more advanced than conventional therapies using corticosteroids and immunosuppressants, offering effective solutions for autoimmune diseases, cancer, transplant rejection, and various infectious diseases, including coronavirus disease 2019. Although they exert low immunosuppressive effects, biological therapies can reactivate specific biological targets associated with infections. This review summarizes the currently available biological therapies and discusses their immunosuppressive mechanisms and clinical applications, highlighting the variations in the types and frequencies of infection recurrence induced by different biological agents. Additionally, this review describes the risk factors associated with various biological agents, thus aiding clinicians in selecting the most appropriate biological therapy.

Severe Occlusive Retinal Vasculitis in an Immunocompetent Patient with Chronic CMV Anterior Uveitis

PURPOSE

We report a unique case of non-necrotizing occlusive retinal vasculitis presenting two years following chronic hypertensive uveitis.

METHODS

Case Report.

RESULTS

A 32-year-old Iraqi woman with a history of Posner-Schlossman Syndrome diagnosed 10 years prior presented with blurred vision and redness in her left eye. Examination demonstrated ocular hypertension, keratic precipitates, and inflammatory cells in the anterior chamber. Quantitative real-time PCR confirmed the presence of cytomegalovirus in the aqueous humor, and dilated posterior segment examination was negative for any signs of intraocular inflammation, retinitis, or vasculitis. Her uveitis workup was otherwise negative, and she was treated with valganciclovir for 6 months. Two years after her initial presentation, she was noted to have a new vitreous hemorrhage in the left eye. Fluorescein angiography demonstrated an occlusive retinal vasculitis with extensive neovascularization without retinitis. Quantitative real-time PCR again demonstrated the presence of cytomegalovirus in the anterior chamber. Her uveitis workup was repeated, which has now returned positive for HLA-B51. She otherwise did not demonstrate any systemic signs of Behcet's Disease. She was restarted on valganciclovir and oral prednisone and referred to rheumatology for consideration of adalimumab initiation. Thus far she has responded very well to treatment.

CONCLUSION

This case highlights the importance of serial posterior segment examinations and HLA-B51 testing in individuals with cytomegalovirus anterior uveitis.

Overview of Cytomegalovirus Ocular Diseases: Retinitis, Corneal Endotheliitis, and Iridocyclitis

Cytomegalovirus (CMV) infection is a significant clinical concern in newborns, immunocompromised patients with acquired immunodeficiency syndrome (AIDS), and patients undergoing immunosuppressive therapy or chemotherapy. CMV infection affects many organs, such as the lungs, digestive organs, the central nerve system, and eyes. In addition, CMV infection sometimes occurs in immunocompetent individuals. CMV ocular diseases includes retinitis, corneal endotheliitis, and iridocyclitis. CMV retinitis often develops in infected newborns and immunocompromised patients. CMV corneal endotheliitis and iridocyclitis sometimes develop in immunocompetent individuals. Systemic infections and CMV ocular diseases often require systemic treatment in addition to topical treatment.

Treatment outcomes in cytomegalovirus anterior uveitis

This retrospective cohort study investigated patients with cytomegalovirus anterior uveitis (CMV AU) and compared treatment outcomes between regional and systemic antiviral therapies. Treatment modalities included topical (2% ganciclovir [GCV] eye drops or 0.2% GCV eye gel) and systemic (intravenous GCV or oral valganciclovir) groups. The comparison parameters included response rates, time to response, recurrence rates, time to recurrence, and complications. Forty-four patients (54.5% male) with a mean age of 56 ± 9.87 years were enrolled, with 31 eyes in the topical group and 13 eyes in the systemic group. The median response time was significantly slower in the topical group (63 days [IQR 28-112]) compared to the systemic group (28 days [IQR 24-59]) (p = 0.04). Treatment response rates were 87.1% (27/31) in the topical group and 100% (13/13) in the systemic group (p = 0.30), while recurrence rates were 37% (10/27) and 69.2% (9/13) (p = 0.056), with a median time to recurrence of 483 days [IQR 145-1388] and 392 days [IQR 203.5-1907.5] (p = 0.20), respectively. In conclusion, both topical and systemic GCV treatments demonstrated favorable outcomes for CMV AU. Systemic GCV showed rapid control of intraocular inflammation.

Reactive Oxygen Species-Responsive Dual Anti-Inflammatory and Antioxidative Nanoparticles for Anterior Uveitis

Anterior uveitis (AU) is an immune-mediated inflammatory disease that results in iritis, cyclitis, glaucoma, cataracts, and even a loss of vision. The frequent and long-term administration of corticosteroid drugs is limited in the clinic owing to the side effects and patient noncompliance with the drugs. Therefore, specifically delivering drugs to inflammatory anterior segment tissues and reducing the topical application dosage of the drug are still a challenge. Here, we developed dual dexamethasone (Dex) and curcumin (Cur)-loaded reactive oxygen species (ROS)-responsive nanoparticles (CPDC NPs) to treat anterior uveitis. The CPDC NPs demonstrated both anti-inflammatory and antioxidative effects, owing to their therapeutic characteristics of dexamethasone and curcumin, respectively. The CPDC NPs could effectively release dexamethasone and curcumin in the oxidizing physiological environment of the inflammation tissue. The CPDC NPs can effectively internalize by activated macrophage cells, subsequently suppressing the proinflammatory factor expression. Moreover, the CPDC NPs can inhibit ROS and inflammation via nuclear transcription factor E2-related factor 2/heme oxygenase-1 (Nrf2/HO-1) pathway activation. In an endotoxin-induced uveitis rabbit model, the CPDC NPs show a therapeutic effect that is better than that of either free drugs or commercial eye drops. Importantly, the CPDC NPs with a lower dexamethasone dosage could reduce the side effects significantly. Taken together, we believe that the dual-drug-loaded ROS-responsive NPs could effectively target and inhibit inflammation and have the potential for anterior uveitis treatment in clinical practice.

Hepatitis B virus and cytomegalovirus coinfection in an older patient: a case report

Cytomegalovirus (CMV) infection involving the skin is relatively rare. We herein report a case involving a man in his late 70s with positive hepatitis B surface antigen who presented with multiform skin lesions, including a papuloid rash, papular urticaria, and purpura. The patient had taken no antiviral drugs for nearly 13 years but had recently developed severe liver injury. Laboratory examination revealed positive CMV immunoglobulin M, CMV polymerase chain reaction result of 1.09 × 102 copies/mL, and a slightly decreased CD4+ cell count; however, the CD8+ T-cell count was within the normal range. A skin biopsy was performed in the region of the papular eruption on the left inner thigh, and the pathologic findings were consistent with CMV infection. After admission, the patient began a combination of antiviral therapy for hepatitis B virus and CMV. After 3 weeks of treatment, the patient was discharged with skin lesions, and his liver function recovered.

Cytomegalovirus-Induced Hypertensive Anterior Uveitis: Diagnostic Challenge in an Immunocompetent Patient

Hypertensive anterior uveitis poses diagnostic challenges owing to its multiple potential etiologies. Cytomegalovirus (CMV) infection is an under-recognized cause that exhibits diverse clinical presentations. This case report focuses on the intricate diagnostic challenge encountered in a 66-year-old immunocompetent patient with CMV-induced hypertensive anterior uveitis. The patient's history, encompassing angle closure glaucoma and topiramate use, contributed to the hypertensive crisis. Initial management included intraocular pressure (IOP)-lowering medication, topiramate discontinuation, and bilateral phacoemulsification, successfully normalizing IOP. However, a subsequent recurrence prompted a detailed investigation. The identification of keratic precipitates and a synechial closed angle led to aqueous humor sampling and polymerase chain reaction (PCR) testing, unveiling the presence of CMV-DNA. Treatment led to a favorable response, resolving ocular inflammation and effectively controlling IOP. This case underscores the complexity of diagnosing and managing CMV-induced hypertensive anterior uveitis, emphasizing the critical role of a comprehensive approach in achieving successful outcomes.

A Prospective Study of Clinical Features of Anterior Uveitis in Taiwan

In this study, we reported the patterns, epidemiology, and clinical features of anterior uveitis (AU) in Taiwan, an area of Eastern Asia. This prospective, cross-sectional case series study was performed to identify patients with AU at two tertiary medical centers (Kaohsiung Chang Gung Memorial Hospital and Kaohsiung Veterans General Hospital) located at the southern Taiwan between December 1, 2018, and March 31, 2020. The clinical diagnoses, ocular presentations, and laboratory data, including the results of the aqueous polymerase chain reaction tests, were investigated in these patients. A total of 112 patients, with a mean age of 48.9 years, were included. Most patients (87.5%) presented with unilateral eye disease, with 30 cases of ocular hypertension at the first presentation (27%). The most common clinical diagnoses were idiopathic AU (37.5%), human leukocyte antigen (HLA)-B27-associated acute AU (25.0%), and herpetic AU (18.8%). Among patients with herpetic AU, cytomegalovirus (CMV) was the most common pathogen (17/21, 81%). Compared to HLA-B27-associated acute AU, CMV-related AU was mostly observed in patients that were older in age, exhibited higher intraocular pressure, more keratic precipitates, greater iris atrophy, and more pseudophakia, but was least reported in those with posterior synechiae. This prospective study identified the pattern and clinical features of AU in southern Taiwan.

Cytomegalovirus-positive Posner-Schlossman syndrome: to compare differences in retinal vessel area density between the affected and non-affected eye using optical coherence tomography angiography

PURPOSE

To analyse differences in the retinal microvasculature in eyes with cytomegalovirus (CMV)-positive Posner-Schlossman syndrome (PSS) compared to the non-affected eyes using optical coherence tomography angiography (OCTA).

METHODS

In this monocentric, observational prospective case series, 25 patients with unilateral CMV-positive PSS were included. We compared the vessel area densities (VAD) in the macula, optic disc, and peripapillary region in PSS-affected and non-affected eyes using OCTA. We compared the visual fields (VF) of the affected and healthy eyes of each patient. The mean deviation (MD) of the VF was analysed together with the retinal nerve fibre layer (RNFL) thickness to evaluate the strength of correlation with the VAD parameters.

RESULTS

The VAD of the peripapillary superficial vascular complex (SVC) is significantly reduced in CMV-positive PSS-affected eyes (46.1 ± 9.3% versus 50.1 ± 6.3%, p = 0.008, adjusted p = 0.048). The VAD of the deeper macular, papillary, and peripapillary layers showed no differences between the affected and non-affected eyes. The mean deviation and the retinal nerve fibre layer thickness had correlations with the VAD of the macula (r = 0.451, p = 0.001, r = 0.553, p < 0.001), the peripapillary SCV (r = 0.430, p = 0.002, r = 0.723, p < 0.001), and the papillary region (r = 0.512, p < 0.001, r = 0.292, p = 0.039). Patients receiving systemic antiviral therapy (SAT) showed better VAD of the peripapillary choriocapillary layer (p = 0.001, no therapy: 31.4 ± 1.9%, SAT: 35.0 ± 1.6%), and choroidal layer (p = 0.009, no therapy: 34.2 ± 0.3%, SAT: 36.3 ± 1.8%) compared to those with no SAT.

CONCLUSION

A lower peripapillary VAD in the SVC might indicate vascular dysfunction as a sign of glaucomatous damage. SAT might have positive effects on the microcirculation in the deep retinal and choroidal layers.

TRIAL REGISTRATION

TRN: DRKS00028266, https://www.drks.de/drks_web/ .

Analysis of Clinical Characteristics of Patients with Recurrent Cytomegalovirus Retinitis after Hematopoietic Stem Cell Transplantation

OBJECTIVE

To analyze and summarize the clinical and imaging characteristics of patients with cytomegalovirus retinitis (CMVR) relapse after hematopoietic stem cell transplantation (HSCT).

METHODS

This retrospective case series study recruited patients with CMVR after HSCT. The study compared the patients with stable lesions and CMV-negative aqueous humor after treatment with those with relapse lesions and a CMV DNA load in aqueous humor which had increased again after treatment. The observation indexes were basic clinical information, best-corrected visual acuity, wide-angle fundus photography, optical coherence tomography (OCT), blood CD4⁺ T lymphocyte count, and aqueous humor CMV load of the patients. We summarized the data and statistically analyzed the differences between the relapse and non-relapse groups, as well as the correlations of the observed indicators.

RESULTS

The study recruited 52 patients with CMVR (82 eyes) after HSCT, of whom 11 patients (15 eyes) had recurrence after treatment (21.2%). The recurrence interval was 6.4 ± 4.9 months. The final best-corrected visual acuity of recurrent patients was 0.3 ± 0.3. The number of CD4⁺ T lymphocytes in recurrence patients at the time of onset was 126.7 ± 80.2/mm³. The median CMV DNA load detected in aqueous humor at the time of recurrence was 8.63 × 10³ copies/mL. There was a significant difference in the CD4⁺ T lymphocyte count between the recurrence and the non-recurrence groups at onset. The onset of visual acuity in recurrence patients was significantly correlated with final visual acuity and recurrence lesion area. The fundus of recurred CMVR showed increased marginal activity of the original stable lesion. Concurrently, yellow-white new lesions appeared around the stable, atrophic, and necrotic lesions. OCT showed new diffuse hyperreflexic lesions in the retinal neuroepithelial layer near the old lesions. Inflammatory punctate hyperreflexes were observed in the vitreous, with vitreous liquefaction and contraction.

CONCLUSION

This study suggests that the clinical features, fundus manifestations, and imaging features of CMVR recurrence after HSCT are different from those at the initial onset. Patients should be closely followed up after their condition is stable to be alert for CMVR recurrence.